Hahaha you are asking a question that many economists still don't know the answer to.
like I always say: economists havent dicover the "heliocentrism" yet. lol
The answer is simple, people place subjective value on things for many reasons including "because it was tuesday". People collect all sorts of things like stamps and old coins that have no direct monetary value today, who wants an old used stamp, well in some cases they are selling for a lot of money. Try to stop thinking of things as televisions and mobile phones, sometimes even a flower can be sold for something. Freedom is priceless 
you simple anser doesn't convince me. stamps and old coins have a nostalgic value which can explain how they start to gain monetary value.